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Choudhury B.,Indian Central Mechanical Engineering Research Institute | Saha B.B.,Kyushu University | Chatterjee P.K.,Indian Central Mechanical Engineering Research Institute | Sarkar J.P.,National Institute of Technology Durgapur
Applied Energy | Year: 2013

Growing energy demand and global climate change are compelling reasons to look for effective utilisation of waste thermal energy and renewable energy resources. Fifteen percent of the electricity produced in the whole world is employed for refrigeration and air-conditioning processes of various kinds. Low-temperature heat operated environment-friendly adsorption cooling systems are emerging as viable alternatives to electricity-driven vapour compression refrigeration systems. Comparatively bigger sizes of adsorption based cooling units, due to their low specific cooling power, are preventing successful commercialization of the technology. Efforts are on to enhance the performance of adsorption systems through improvements in adsorbents properties, use of advanced cycles, etc. Recent application of nano-technology in the development of adsorbent material may be a big step forward towards making this technology competitive with available technologies in the market. This paper traces the evolution of the technology and analyses the obstacles to wide spread use of adsorption chillers. © 2012 Elsevier Ltd.

Karmakar M.K.,Indian Central Mechanical Engineering Research Institute | Datta A.B.,Indian Central Mechanical Engineering Research Institute
Bioresource Technology | Year: 2011

The objective of this study was to investigate the process of generating hydrogen rich syngas through thermo chemical fluidized bed gasification of biomass. The experiments were performed in a laboratory scale externally heated biomass gasifier. Rice husk had been taken as a representative biomass and, steam had been used as the fluidizing and gasifying media. A thermodynamic equilibrium model was used to predict the gasification process. The work included the parametric study of process parameters such as reactor temperature and steam biomass ratio which generally influence the percentage of hydrogen content in the product gas. Steam had been used here to generate nitrogen free product gas and also to increase the hydrogen concentration in syngas with a medium range heating value of around 12MJ/Nm3. © 2010 Elsevier Ltd.

Chatterjee D.,Indian Central Mechanical Engineering Research Institute
Numerical Heat Transfer, Part B: Fundamentals | Year: 2010

A lattice Boltzmann (LB) simulation strategy is proposed for the incompressible transport phenomena occurring during macroscopic solidification of pure substances. The proposed model is derived by coupling a passive scalar-based thermal LB model with the classical enthalpy-porosity technique for solid-liquid phase-transition problems. The underlying hydrodynamics are monitored by a conventional single-particle density distribution function (DF) through a kinetic equation, whereas the thermal field is obtained from another kinetic equation which is governed by a separate temperature DF. The phase-changing aspects are incorporated into the LB model by inserting appropriate source terms in the respective kinetic equations through the most formal technique following the extended Boltzmann equations along with an appropriate enthalpy updating scheme. The proposed model is validated extensively with one- and two-dimensional solidification problems for which analytical and numerical results are available in the literature, and finally, it is used for solving a benchmark problem, the Bridgman crystal growth in a square crucible. Copyright © Taylor & Francis Group, LLC.

Bhattacharya D.,Indian Central Mechanical Engineering Research Institute
Inorganic Chemistry Communications | Year: 2013

A new self-assembled dinuclear rhenium(I) tricarbonyl complex, [Re 2(CO)6(μ-η4-C2O 4)(μ-4,4′-tmdp)] (1) featuring a bis-chelating oxalato dianion (μ-η4-C2O4, H2C 2O4 = oxalic acid) connects two fac-Re(CO)3 cores, which are interconnected by a neutral ditopic N-donor clip ligand, that is, 4,4′-trimethylenedipyridine (μ-4,4′-tmdp) has been elegantly synthesized in high yield in a one-step reaction. Compound 1 was characterized by elemental analysis, IR, ESI-MS, TGA and single-crystal X-ray diffraction analyses. The titled complex represents the first dirhenium(I) metallacycle which shows the coexistence of two emissive pathways at room temperature, one populates an emissive 3π-π* state and the other populates a 3MLCT state. © 2013 Elsevier B.V.

Chatterjee D.,Indian Central Mechanical Engineering Research Institute
Numerical Heat Transfer; Part A: Applications | Year: 2010

The fluid flow and heat transfer characteristics around two isothermal square cylinders arranged in a tandem configuration with respect to the incoming flow within an insulated vertical channel at low Reynolds number range (1Re30) are estimated in this article. Spacing between the cylinders (S) is fixed at four widths of the cylinder dimension (d) and, the blockage parameter (B) is set to 0.25. The buoyancy-aided/opposed convection is examined for the Richardson number (Ri) ranges from -1 to 1 with a fixed Prandtl number (Pr) of 0.7. The transient numerical simulation for this two-dimensional, incompressible, laminar flow and heat transfer problem is carried out by a finite volume code based on the PISO algorithm in a collocated grid system. The results suggest that the flow remains steady for the entire range of parameters chosen in this study. The representative streamlines, vorticity, and isotherm patterns are presented to interpret the flow and thermal transport visualization. Additionally, the time average drag coefficient (CD) as well as time and surface average Nusselt number (Nu) for the upstream and downstream cylinders are determined to elucidate the effects of Re and Ri on flow and heat transfer phenomena. Copyright © Taylor & Francis Group, LLC.

Chatterjee D.,Indian Central Mechanical Engineering Research Institute
International Communications in Heat and Mass Transfer | Year: 2014

We establish through numerical simulation a dual role played by the superimposed thermal buoyancy in controlling the boundary layer separation around bluff obstacles. The work essentially demonstrates the influence of superimposed thermal buoyancy on flow around bluff obstacles of circular and square cross sections in aiding/opposing and cross buoyancy configurations. For the aiding/opposing configuration we show two phenomena such as the suppression of flow separation which occurs at relatively low Reynolds numbers (10-40) and the suppression of vortex shedding at a moderate range of Reynolds numbers (50-150). In the cross buoyancy configuration, the initiation of vortex shedding by the introduction of thermal buoyancy is shown at relatively low Reynolds numbers (10-40). Hence, depending on the direction of interaction with the free stream flow, the buoyancy sometimes stabilizes the flow and sometimes destabilizes the flow. Accordingly, there is a dual role of superimposed thermal buoyancy in controlling the boundary layer separation around bluff obstacles. Such duality cannot be observed in case of other agents such as rotation, magnetic force which also control the boundary layer separation around bluff obstacles. © 2014 Elsevier Ltd.

Chatterjee D.,Indian Central Mechanical Engineering Research Institute
Numerical Heat Transfer; Part A: Applications | Year: 2013

Numerical simulations are performed to understand the thermo-magneto- convective transport of fluid and heat in a vertical lid-driven square enclosure following a finite volume approach based on the SIMPLEC algorithm. The enclosure is filled with an electrically conducting fluid and having a heated source on the right vertical wall. Two different types of sources, such as a semicircular and a rectangular one, are considered. Both the top and bottom horizontal walls and the right vertical wall, except the source of the enclosure, are assumed insulated and the left vertical wall and the sources are kept isothermal with different temperatures. The left vertical wall is also translating in its own plane at a uniform speed, while all other walls are stationary. Two cases of translational lid motion, viz., vertically upward and downward are considered. A uniform magnetic field is applied along the horizontal direction normal to the translating wall. Shear forces due to lid motion, buoyancy forces as a result of differential heating, and magnetic forces within the electrically conducting fluid act simultaneously. Heat transfer due to forced flow, natural convection, and Joule dissipation are taken into account. Simulations are conducted for various controlling parameters, such as the Rayleigh number (103 ≤ Ra ≤ 105), Hartmann number (0 ≤ Ha ≤ 100), and Joule heating parameter (0 ≤ J ≤ 5), keeping the Reynolds number based on lid velocity fixed as Re = 100. The flow and thermal fields are analyzed through streamline and isotherm plots for various Ha and J. Furthermore, the pertinent transport quantities such as the drag coefficient, Nusselt number, and bulk fluid temperature are also plotted to show the effects of Ha, J, and Ra on them. © 2013 Copyright Taylor and Francis Group, LLC.

Ikkurti H.P.,Indian Central Mechanical Engineering Research Institute | Saha S.,Indian Central Mechanical Engineering Research Institute
Renewable and Sustainable Energy Reviews | Year: 2015

Increasing incentives for building integrated photovoltaic (BIPV) generation at local/major grid levels established it as a viable decentralized option promising large growth potential. BIPV systems - comprising photovoltaic (PV) modules installed on available building surfaces and downstream energy conversion devices - afford improvement of energy efficiency of buildings and partially or fully dispenses with the supply of centralized grid power. This paper presents a comprehensive techno-economic review, covering the technical as well as commercial aspects of microinverter technology. Advantages of microinverters over conventional inverters are detailed along with a discussion on economics of its installation in distributed solar generation systems. Different power converter topologies reported in the available literature are presented. The paper also reports the historical development of commercial microinverters and their present status in the Photovoltaic (PV) market. Survey of the available products from some of the technology leaders in the market has been done and their specifications are tabulated. The paper concludes with a discussion on the necessities of the next generation microinverters for increased penetration in the PV market. © 2015 Elsevier Ltd.

Chatterjee D.,Indian Central Mechanical Engineering Research Institute
Catalysis Communications | Year: 2010

Visible light assisted hydrogen evolution from of water has been achieved over the surface of dye modified TiO2 semiconductor. Thionine, eosin Y, rhodamine B, methylene blue, nile blue A and safranine O were used for surface modification of TiO2 semiconductor photocatalyst. Upon prolonged illumination (15 h) with visible light (using a 150 W Xenon lamp) production of H2 in micro-mole level (600-1500 μmol) has been achieved at ambient conditions. Efficacy of the photocatalytic system towards hydrogen evolution is plausibly governed by the excited state redox properties of the dyes adsorbed onto the surface of the TiO2 photocatalyst. © 2009 Elsevier B.V. All rights reserved.

Chatterjee D.,Indian Central Mechanical Engineering Research Institute
Numerical Heat Transfer; Part A: Applications | Year: 2012

Influences of superimposed thermal buoyancy on the initiation of vortex shedding process behind bluff obstacles (such as circular and square cylinders in 2-D) in cross-flow at low Reynolds numbers (10≤Re≤40) are discussed. The flow which is steady and separated at this Reynolds number range eventually becomes unsteady periodic with the introduction of thermal buoyancy. The aim here is to numerically predict the critical value of the buoyancy parameter (Richardson number, Ri) for the onset of vortex shedding. The critical Ri is found to have a decreasing tendency for both types of cylinder geometries with increasing Re. © 2012 Copyright Taylor and Francis Group, LLC.

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